U.S. Pat. No. 5,451,128 (Hattersley) discloses a cutter blade having a cutting face. Formed in the cutting face are a plurality of spaced apart slots, each slot having forward and rearward sidewalls. A tooth is removably received in each of the slots, each tooth having a top surface extending above the cutting face and having forward and rearward sidewalls. The top surface of each tooth has a forward cutting edge and a rearward reduced height step section. A retention bar is provided for each tooth, each retention bar having a forward end that is received in the step section. A pin extending through an opening in each retention bar is threadably connected to the cutting face. By tightening the threaded pin the retention bar retains each tooth during cutting operation so that the tooth sidewalls frictionally engage the slot sidewalls and by unthreading the pin the retention bar may be rotated to permit removal and replacement of each of the teeth.
U.S. Pat. No. 7,128,165 (McGivery) discloses a system and method of cutting a core out of a finished surface for keyhole excavation, using a truck with a turret to which a support arm supporting the cutter assembly is mounted, and a stabilizing member remote from the turret, which allows the turret to be rotated about its complete arc of motion while stabilizing the support arm at any desired position about the truck. In a first embodiment the invention comprises an upstanding support rim affixed to or integrated into the bed of the truck. In a further embodiment the invention comprises a support member affixed to the horizontal arm and supported by the truck bed. This is disclosed as making the keyhole excavation procedure safer and more precise, and allowing a larger-depth cutting head to be used in order to penetrate thicker finished surfaces. In the preferred embodiment the cutter head is provided with a pilot which creates a pilot hole in the core that may facilitate removal, manipulation and replacement of the core, and may improve the integrity of the reinstated core.